1. Field of the Invention
The present invention relates to a verification method for checking a communication module. More specifically, the present invention discloses a verification method that is able to retrieve an original data according to a data packet.
2. Description of the Prior Art
In the information era, communication for various digital information is already a part of daily life. Under this tendency, all mobile phones, personal digital assistants (PDA), computers and information apparatuses (IA), emphasize the ability of digital information communications. Therefore, the research and development of communication modules becomes an important part of the information industry.
When developing the communication module, it is a necessary step to check and debug the communication module for ensuring the communication module is capable of operating. One test method is to connect the output of the communication module to a logic analyzer, in order to analyze whether the digital signal which is transmitted from the communication module is correct or not, so as to achieve the purpose of verification.
In general, transmitted digital communication signals are formatted to comply with a strict communication protocol, in order to achieve information exchange. The Bluetooth signal transmission system, put forth by the information industry circle and academic circles, defines a format to form packets for data transmission . Please refer to FIG. 1. FIG. 1 is a diagram of a transmitter and a receiver during signal transmission using Bluetooth communication technology. The transmitting end 10 comprises a communication module 20 and a radio frequency interface 30. The transmitting end 10 is able to signal the receiving end 50 over a channel 40. The receiving end comprises another radio frequency interface 55 and a receiving module 57, for processing the received signal. In the transmitting end 10, the transmitted data is formed into an information packet 32 by the communication module 20, then the information packet 32 is radiated by the radio frequency interface 30. The communication signal can be transmitted to the receiving end 50 using the channel 40 (for example, wireless communication or infrared ray transmission). When the receiving end 50 receives the communication signal, it converts the communication signal back to the information packet 32 by utilizing the internal radio frequency interface 55. Then, the receiving module 57 in the receiving end 57 obtains the data portion of the information packet 32.
Regarding processes for formation of the information packet by the communication module 20 in the transmitting end, and handling by the receiving module 57 in the receiving end, further description is as follows. As the transmitting end 10 transmits data, the data corresponds to the original data signal 12 in the communication module 20. Further, the communication module 20 also generates a clock code 16 and a first original header signal 18. The first original header signal 18 is capable of forming a first check signal 18b by using a first coding method. A first header signal 22 can be formed by combining the first original header signal 18 and the first check signal 18b. The first header signal 22 is encoded as an output header signal 24 by using the clock code 16 according to the second coding method. Further, the original data signal 12, corresponding to the data, is encoded as the second data signal 28 by use of the clock code 16 according to a data coding method 35. At last, the output header signal 24 combines with the second data signal 28 to form the data packet 32. Please note that, in the process of forming the output header signal 24 by using the second coding method 45, and forming the second data signal 14 by use of the data coding method 35, the clock code 16 is required. In other words, the output header signal 24 and the second data signal 28, which are in the information packet 32, both relate to the clock code 16. Even if using the same first header signal 22, but a different clock code, then the output header signal formed by the second coding method 45 is different. Also, if using the same original data signal 12, but a different clock code 16, then the second data signal 28 formed by the data coding method 35 is not the same.
For the sake of retrieving the data in the information packet 32 correctly, when the transmitting end 10 builds a connection with the receiving end 50, the transmitting end 10 whitens the clock code 16 with a fixed form, then transmits to the receiving end. If the receiving module 57 in the receiving end 50 is able to retrieve the clock code 16, then it acknowledges the transmitting end 10. Following, when the receiving module 57 receives the packet 32 demodulated by the radio frequency interface 55, the receiving module 57 is able to decode the second data signal 28 of the data packet 32 into the original data signal 12 by using the second data decoding method 25 and the clock code 16 of the receiving module 57. Therefore, the receiving end 50 can obtain the data from the original data signal 12 and achieve the purpose of transmission. Further, the output header signal 24 of the information packet 32 can be decoded into the first header signal 22 by using the third decoding method 67 and the clock code 16. As mentioned before, in the process of forming the output header signal 24 from the first header signal 22, and forming a second data signal 28 from the original data signal 12, the clock code 16 is required. Of course, in the process of decoding the output header signal 24 into the first header signal 22, and decoding the second data signal 28 into the original data signal 12, the same clock code 16 is also required, so as to obtain the correct result after decoding.
Conventionally, when testing the communication module 20, the logic analyzer must be used to analyze the data packet 32 which is transmitted from the communication module 20, then the data in the data packet 32 must be checked for whether it is the same as the data of the original data signal 12 or not, so as to verify the communication module 20. As mentioned before, to decode the original data signal 12 from the information packet 32, the correct clock code 16 must be used. However, the communication module 20 transmits the clock code 16 to the receiving end 50 only in the early stage of the connection. established. In the following stages of the communication, the clock code is not transmitted. For completely verifying, several hours are required to do checking for the communication module. Although only checking data communication for several minutes, thousands of megabits of digital data are transmitted and the associated verification is very difficult. In addition providing signal pins to obtain the clock code 16 of the communication module 20, the hardware design of the communication module 20 must be changed and additional pins are required.